This study will investigate changes in neuropsychological and psychosocial function in epileptic adults and children over time. One hundred adults, already tested with the neuropsychological battery for epilepsy and the Washington Psychosocial Seizure Inventory, will be re-tested five years from original testing. Two hundred and thirty children will be tested with age-appropriate version of the neuropsychological battery on two occasions, separated by two and one-half years; in 70 of these, original testing has been done and both two and one-half year and five year testing will be done. Standardization will be done by testing a control group of non-epileptic children. Data on longitudinal psychosocial function in children will be obtained by administration of an age-modified psychosocial interview on two occasions separated by two and a half years. Correlation of change in neuropsychological and psychosocial functions with seizure type, seizure frequency, age at onset, duration of seizure disorder and medication will be sought.